In general, washing machines may be classified into a pulsator-type washing machine, which uses or generates a water current by rotation of a pulsator on a bottom surface of a washing tub, an agitator-type washing machine, which uses a central agitator to wash laundry (e.g., using friction), and a drum type washing machine, which uses gravity (e.g., a vertical drop of the laundry resulting from rotation of a drum in the washing machine) to wash laundry.
A drum type washing machine is disclosed in various documents, including Korean Patent Registration No. 10-0400969 and the like, and the drum type washing machine in the related art includes each of a tub 11 containing wash water and a drum 12 inside a main body 10.
Accordingly, during washing, a door 18 in or on a front surface of the washing machine is opened, laundry is put into the tub 12, and water is supplied to the tub 12 after the laundry is put into the tub 12, to perform washing.
Power from a washing motor 13 is transferred to a drum shaft 15 through a belt 13a, so that the drum 12 is rotated, and a lifter 20 inside the drum 12 lifts and drops the laundry so that washing is performed.
A spring 9 and a damper 8 are connected to and support the drum 12 to attenuate vibrations generated by the rotation of the drum 12 during washing. The spring 9 and the damper 8 are generally fixed to the main body 10.
During spin-drying, a drain pump 17 is operated so that water is drained through a drain hole 16 and a drain hose 19 connected to a lower portion of the tub 11.
As described above, the drum type washing machine in the related art commonly further includes the tub 11 in addition to the drum 12. The reason is that the tub 11 contains the wash water, while washing is performed in the drum 12 inside the tub 11.
However, the tub 11 is generally formed of a plastic material, and accumulated mold, dirt or other foreign substances form in the tub 11 or on an inner surface of the tub 11 when the tub 11 is used over a long period of time. However, it is difficult to clean the tub 11, due to the presence of the drum 12. as a result, the unclean surface of the tub 11 may corrode, weaken, and/or contaminate the laundry (which may cause a skin irritation or disease).
The pulsator type washing machine as well as the drum type washing machine that include the tub may have such problems.